斯威夫特：使用过滤结构数组UISearchController / predicates [英] Swift: Filtering an array of structures using UISearchController/Predicates

问题描述

想知道，如果有人可以帮助我使用predicates斯威夫特过滤。

Wondering if someone could help me out with filtering using predicates in Swift.

我有我使用填充一个UITableView一个有些凌乱的数据源。数据源是结构的数组。结构体定义如下：

I have a somewhat messy datasource that I am using to populate a UITableView. The data source is an array of structures. The struct is defined as follows:

struct Exercises {
    let category: String
    let name : String
    let x_seed: [Double]
    let y_seed: [Double]
    let hasMult: Bool
}

现在在我的tableview控制器我抱着结构的数组包含所有表的数据。

Now in my tableview controller I'm holding an array of structures that contains all of the data for the table.

class MainTableViewController: UITableViewController, UISearchResultsUpdating {


var exercises = [Exercises]()
var filtered_exercises = [Exercises]()
var resultSearchController = UISearchController()

override func viewDidLoad() {
    super.viewDidLoad()

    // MARK: - Table view data source
    self.exercises = [
        Exercises(category:"Sports", name:"Bowling", x_seed:[125,155,185], y_seed:[3.00, 3.73, 4.43], hasMult:false),
        Exercises(category:"Sports", name:"Water Polo", x_seed:[125,155,185], y_seed:[10.00, 12.40,14.80], hasMult:false),
        Exercises(category:"Sports", name:"Handball", x_seed:[125,155,185], y_seed:[12.00, 14.87, 17.77], hasMult:false),
        Exercises(category:"Sports", name:"Dancing", x_seed:[125,155,185], y_seed:[3.00, 3.73, 4.43], hasMult:true),
        Exercises(category:"Sports", name:"Frisbee", x_seed:[125,155,185], y_seed:[3.00, 3.73, 4.43], hasMult:false),
        Exercises(category:"Sports", name:"Volleyball", x_seed:[125,155,185], y_seed:[3.00, 3.73, 4.43], hasMult:false),
        Exercises(category:"Sports", name:"Archery", x_seed:[125,155,185], y_seed:[3.50, 4.33, 5.17], hasMult:false),
        Exercises(category:"Sports", name:"Golf", x_seed:[125,155,185], y_seed:[3.50, 4.33, 5.17], hasMult:true)]

    self.resultSearchController = ({
        let controller = UISearchController(searchResultsController: nil)
        controller.searchResultsUpdater = self
        controller.dimsBackgroundDuringPresentation = false
        controller.searchBar.sizeToFit()

        self.tableView.tableHeaderView = controller.searchBar

        return controller
    })()

    self.tableView.reloadData()
}

我想要做的就是过滤的练习的基础上，姓名字段阵列和填充新的数据源filtered_exercises填补的tableview。我不知道如何包装我围绕如何在这种情况下使用predicates头。

What I would like to do is filter the exercises array based on the 'name' field and populate a new datasource filtered_exercises to fill the tableview. I am not sure how to wrap my head around how to use predicates in this situation.

// Search functionality 
func updateSearchResultsForSearchController(searchController: UISearchController)
{
    filtered_exercises.removeAll(keepCapacity: false)

    let searchPredicate = NSPredicate(format: "SELF CONTAINS[c] %@", searchController.searchBar.text!)
    // ??????????????

    self.tableView.reloadData()
}

我知道我可以读取所有的名字在一个字符串数组，并显示在tableview中容易。问题是，我需要preserve结构作为数据包含有被传递到其他视图控制器。

I know I could read all of the names in a string array and display that in the tableview easily. The problem is that I need to preserve the structures as the data contained there is passed onto other view controllers.

所以，我怎么能过滤结构的数组？

So, How can I filter an array of structs?

谢谢！

推荐答案

如果你不坚持 NS predicate （不明白了一个道理，为什么你应该因为你不使用 NSFetchRequest ，...），这里的code：

If you do not insist on NSPredicate (don't see a reason why you should since you're not using NSFetchRequest, ...), here's the code:

struct Exercises {
  let category: String
  let name : String
  let x_seed: [Double]
  let y_seed: [Double]
  let hasMult: Bool
}

let exercises = [
  Exercises(category:"Sports", name:"Bowling", x_seed:[125,155,185], y_seed:[3.00, 3.73, 4.43], hasMult:false),
  Exercises(category:"Sports", name:"Water Polo", x_seed:[125,155,185], y_seed:[10.00, 12.40,14.80], hasMult:false),
  Exercises(category:"Sports", name:"Handball", x_seed:[125,155,185], y_seed:[12.00, 14.87, 17.77], hasMult:false),
  Exercises(category:"Sports", name:"Dancing", x_seed:[125,155,185], y_seed:[3.00, 3.73, 4.43], hasMult:true),
  Exercises(category:"Sports", name:"Frisbee", x_seed:[125,155,185], y_seed:[3.00, 3.73, 4.43], hasMult:false),
  Exercises(category:"Sports", name:"Volleyball", x_seed:[125,155,185], y_seed:[3.00, 3.73, 4.43], hasMult:false),
  Exercises(category:"Sports", name:"Archery", x_seed:[125,155,185], y_seed:[3.50, 4.33, 5.17], hasMult:false),
  Exercises(category:"Sports", name:"Golf", x_seed:[125,155,185], y_seed:[3.50, 4.33, 5.17], hasMult:true)
]

let options = NSStringCompareOptions.CaseInsensitiveSearch | NSStringCompareOptions.DiacriticInsensitiveSearch

// Filter exercises by name (case and diacritic insensitive)
let filteredExercises = exercises.filter {
  $0.name.rangeOfString("Ol", options: options) != nil
}

let filteredExerciseNames = ", ".join(filteredExercises.map({ $0.name }))
println(filteredExerciseNames)

它打印的水球，排球，高尔夫球的

这篇关于斯威夫特：使用过滤结构数组UISearchController / predicates的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！